/*
 * Copyright (c) 2006,2007 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 */
#include "constant-velocity-helper.h"

#include "box.h"
#include "rectangle.h"

#include "ns3/log.h"
#include "ns3/simulator.h"

namespace ns3
{

NS_LOG_COMPONENT_DEFINE("ConstantVelocityHelper");

ConstantVelocityHelper::ConstantVelocityHelper()
    : m_paused(true)
{
    NS_LOG_FUNCTION(this);
}

ConstantVelocityHelper::ConstantVelocityHelper(const Vector& position)
    : m_position(position),
      m_paused(true)
{
    NS_LOG_FUNCTION(this << position);
}

ConstantVelocityHelper::ConstantVelocityHelper(const Vector& position, const Vector& vel)
    : m_position(position),
      m_velocity(vel),
      m_paused(true)
{
    NS_LOG_FUNCTION(this << position << vel);
}

void
ConstantVelocityHelper::SetPosition(const Vector& position)
{
    NS_LOG_FUNCTION(this << position);
    m_position = position;
    m_velocity = Vector(0.0, 0.0, 0.0);
    m_lastUpdate = Simulator::Now();
}

Vector
ConstantVelocityHelper::GetCurrentPosition() const
{
    NS_LOG_FUNCTION(this);
    return m_position;
}

Vector
ConstantVelocityHelper::GetVelocity() const
{
    NS_LOG_FUNCTION(this);
    return m_paused ? Vector(0.0, 0.0, 0.0) : m_velocity;
}

void
ConstantVelocityHelper::SetVelocity(const Vector& vel)
{
    NS_LOG_FUNCTION(this << vel);
    m_velocity = vel;
    m_lastUpdate = Simulator::Now();
}

void
ConstantVelocityHelper::Update() const
{
    NS_LOG_FUNCTION(this);
    Time now = Simulator::Now();
    NS_ASSERT(m_lastUpdate <= now);
    Time deltaTime = now - m_lastUpdate;
    m_lastUpdate = now;
    if (m_paused)
    {
        return;
    }
    double deltaS = deltaTime.GetSeconds();
    m_position.x += m_velocity.x * deltaS;
    m_position.y += m_velocity.y * deltaS;
    m_position.z += m_velocity.z * deltaS;
}

void
ConstantVelocityHelper::UpdateWithBounds(const Rectangle& bounds) const
{
    NS_LOG_FUNCTION(this << bounds);
    Update();
    m_position.x = std::min(bounds.xMax, m_position.x);
    m_position.x = std::max(bounds.xMin, m_position.x);
    m_position.y = std::min(bounds.yMax, m_position.y);
    m_position.y = std::max(bounds.yMin, m_position.y);
}

void
ConstantVelocityHelper::UpdateWithBounds(const Box& bounds) const
{
    NS_LOG_FUNCTION(this << bounds);
    Update();
    m_position.x = std::min(bounds.xMax, m_position.x);
    m_position.x = std::max(bounds.xMin, m_position.x);
    m_position.y = std::min(bounds.yMax, m_position.y);
    m_position.y = std::max(bounds.yMin, m_position.y);
    m_position.z = std::min(bounds.zMax, m_position.z);
    m_position.z = std::max(bounds.zMin, m_position.z);
}

void
ConstantVelocityHelper::Pause()
{
    NS_LOG_FUNCTION(this);
    m_paused = true;
}

void
ConstantVelocityHelper::Unpause()
{
    NS_LOG_FUNCTION(this);
    m_paused = false;
}

} // namespace ns3
